Improved method op converting cast-iron into steel



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i tiratori tutta wizwlwstse @sind lttit Letters Patent No. 86,536, dated February 2,1869.

IIMPROVED METHOD OF CONVERTING- CAST-IRON NTO STEL.

The Schedule referred to in these Lettee Patent and making part' of the E To all whom 'it 'may concern:

Be it known that I, ALEXANDER Hanan, of the city and county ofPhilznlelphia, in the State of Pennsylvania, have invented a newgaud improved Method of Gouvcrtiug Cast-Iron into Steel, of which the following is a full, clear, and exact description.

The object of my invention is to convert cast-iron into steel by a continuons operation.

The lirstpa-rt of my invention relates to the furnace in which the cast-iron to be converted into steel is melted; and my improvement consists in forming a bed, or hearth, for the furnace, of a mixture of nitrate ot'soda, one volume; pulver-ized charcoal, tive volumes; slaked lime, tive volumes. These ingredients are to be covered with a layer, half an inch in depth, of pulverized ihnenite, magneu'te, or l `ranklinite, mixed with one-fourth its volume ot' slakcd lime, made into paste with water. g

The next part of my .action consists in oombinin,` a furnace to melt thtI iron, an insulated ladle to receive the melted mctal/li'om the furnace, a. stack, through which the metal flows, an electric current actua,r ou the flowing metal, and a converting-inrnace.

My invention further consists in forming a bed in thc ladle, ofthe following ingredients: alkaline nitratcs,t\vo pa s; peroxide ofmanganese, one part;carburets, three parts.

The next part of my invention consists in combiniino`- a reverheratory furnace with a stack, through which the melted metal falls, and within which it is exposed to a' blast, so that the stack shall serve as a chimney for the furnace. l

My invention further consists in combining two or more lires with a reverbcratory furnace, and with a showering-stack, which also serves as a common chimncy for the tires, as hereinafter set forth.

In the accompanying,r drawings, which show convenient apparatus for carrying out my invention- Figure l is a view, partly in section `and partly in elevation, of a single convcrting-tiirnacc and separate chimney; l

Figure 2 is a vertical Section through the converting-furnace and stack; and l Figure 3, a view of my improved apparatus, adapted to a double converting-furnace, and a stack, without a chinmey. 'E

lhc bottom of the furnace A is covered with a bed of nitrate of soda, one volume; pulvcrized charcoal, live volumes; slaked lime, tive volumes. This mixture is covered with alayer, about half an inch deep, of pnlverized ilmeuitc, magnetite, or llranklinit-e, mixed with one-ihurth its volume of slakod lime, made into paste with water.

When dry, the furnace is charged with pig-iron and coal, in the usual way.

At suitable periods, the molten metal is run through al trough, a, into ai ladle, B, electrically insulated, in any proper well-known way, and connected with the negative pole of a strong electric battery, by a wire, af.

I form a bed in this ladle, of two parts of alkaline nitrates, one. part of peroxide of manganese, and three parts of carburcts. As the action of these ingredients often causes ebullition of the iron, I hinge a cover, B, on the ladle, so that it may be tipped to one side, as shown in ii. 3. This oo ver is of the shape of an inverted funnel, and is 'open at the top, to allow the gases to escape ti'om tlie ladle.

A spout, b, conducts the melted irou into a stack, G, into which it falls, heinoscattered into spray by acone, D, secured on suitable ars, c, some distance below the top of the stack, and suitably protected from heat by tire-clay, or eqnivalentlmeans.

.This cone may be so! constructed as to be raised or lowered, to regulate tl r scattering of the met-al, (and also the length of timo ihe metal is exposed tothe current,) and is pcrforatub'so as to rcceivethe other er positive pole of the battery, the wire p of which must of course be suitably insulated.

It will be seen that, by my mode of construction, 'the current of falling metal itself forms a connecting-link between the two poles ofthe battery.

The stack C, iu this instance, is formed of au outer casing, E, of iron, with an internal lining, c, of firebriok, or briclg so arranged as to leave an annular space, e2, between them.

rlhis space serves as a blowing-chamber, through which a high-pressure blast of compressed air is forced into the stack, by numerous openings, j, at diicrent elevations.

'lhe hydrogen of the furnace, or the oxygen of the blast, encounters the falling current of metal just as it is chemically separated from its impurities by the electric current, and immediately unites with the carbon, forming curhurettcd hydrogen or oxygen, (as the case may be,) which, by its combustion, destroys or eliminates the other impurities ofthe iron.

In figs. l and 2,21, tire-place, G, is shown, as arranged near the stack.

'lhe fuel is placed 011 a gra-te, It.

Mingled jets of steam and air are introduced into the lire-place, below the grate, through pipes Iz',li-o1u any proper apparatus. I

'lhc oxygen of the steam is consumed by the fire, and the remaining products of combustion (mainly carburetted hydrogen) pass over into the rcverberatory furnace O, being mingled, at the bridge j, with jets of air, entering through apertures, li l', in the lirechamber, by which meansan intense heat is produced.

The draft can be regulated to any desired velocity, by valves on the inlet pipes I i, L l, and by the damper M on thc chimney.

hc hearth 0 is covered with a layer composed of a mixture of charcoal-dust, oxide of manganese, and a small quantity of slaked lime Pig-iron is laid on this bed, and melted by the heat produced, as above described.

The products of combustion escape up the stack C, through the trough K, by which the purified iron descends into the furnace 0, and keeps the stack heated.

The iron, as it flows from the stack, is decarbonized, and lningles with the melted iron ou the hearth 0, and

the mixture of these two produces steel of goodquality, l

which is cast into ingots in the 'usual way.

If the metal on the hearth is too highly carbonized,

' it is decarbonized by being exposed to the blast a suflicient length of time. If not carbonized enough, afew pieces of carbonized iron are thrown in and melted.

In fig. 3, I have shown a modification of the apparatus shown in gs. l and 2. rlhe modification consists in arranging two or more fires, G, around a ceutral reverberatory furnace, 0,- placing,r the stack C over the furnace, and using this stack alone as the chimney.

works, to eeonomize fuel, and to increase the working.- capacity of the furnace materially.

What I claim las my invention, and desire to secure by Letters Patent, is-

1. The combination of nitrate of soda, charcoal, slaked lime, and ilmenite, magnetite, or Franklinite, substantially as set forth, to form the bed of the melting-furnace.

2. The combination of a melting-furnace, an insulated ladle, a showering-stack, an electric current, and a converting-furnace, substantially as set forth.

A3. The bed for the ladle, composed of alkaline nitrates, peroxide of manganese, and carburets, substantially` as set forth.

4. The combination of a reverheratory or convertingfurnace with a showering-stack, substantially as set forth.

5. The combination, substantially as set forth, with two or more res, of a reverberatory or converting-furnace and a showering-stack, through which the molten metal and the products of combustion pass.

f I tsillveyivllelieetUwe .hereuntosubscribedmy naf A. HAMAR. Witnesses:

WM. B. DAiIToN, TH. PRATT Porrs. 

